Apparatus for reclaiming metals



May 31 1927.

C0 sa/Ee r Arrae/vfr.

' l 630,361 May 31 1927 T. D. s-rAY. ET AL.

APPARATUS FOR RECLAIMING METALS I Fi16d`00t. 28. 1921 4 Sheets-Sheet 2V 2'0. .STAY C'. 0. 7255/'52 May 31 1927.

T. D. STAY ET AL APPARATUS FOR RECLAIMING METALS Filed. Oc. 2 8. 1921 4 Sheets-Shet 3 Waff/vrees; Z' 57:41/

Affare/vf Y T. D; STAY ET AL APPARATUS FOR RECLAIMING METALS Filed Oct. 23, 1921 4 Sheets-Sheet 4 Wwf Patented May 31, 1927.

UNITED STATES PATENTy OFFICE.

lTI1IIE|IRON D. STAY AND CHARLES 0. TESSIER, OF CLEVELAND,` OHIO, ASSIGNORS, BY MESNE-ASSIGNMENTS, TO ALUMINUM COMPANY 0F AMERICA, OF PITTSBURGH,

PENNSYLVANIA, A -CORPORATION OF PENNSYLVANIA.

APPARATUS FOR BECLAIMING METALS.

Application sied october as, 1921. serial No. 511,021.

This invention relates to apparatus for relining metals and is particularly concerned with mechanical means for carrying out an improved metal reclaiming process adapted to the lighter, more readily oxidizable v metals which is disclosed in co-pending ap- 511,060 filed Oct. 28,

ing it in a molten metal melting bath, forv stirring the bath .without causing harmful agitation thereof andfor concentratingdross and other 4impurities carried by the scrap metal in a mannereto facilitate separation of the impurities and clean metal.

Another object is to construct meansfor `finely-dividing the dross and other impurities of a-metal melting-bath and maintain- 4ing it in a finely-divided state, and for quickly cooling and separating from the dross the molten metal associated therewith, all in a manner to prevent undue oxidation of the molten metal and to permit immedi-l ate re-melting of the recovered metal: c

Another object Iis to construct a stlrring paddle for use in a metalmelting furnace 'which shall b e capable of creating a desired stirring and circulation of the molten metal bath without harmful agitation thereof, for quickly submerging in the bath finely-divided scrap metal to be melted, and for causing a concentration of dross or impurities at the surface of the molten metal.

' Another' object is to construct a mechani- I cal separating device for separating molten metal from dross comprising a new and improved combination of movlng screens and tables so arranged as to cooperate in liberating the metal in molten form from the dross and in suddenly chilling the metal and finally complet-ing the separation of the metal from the dross. f

Another object is to provide com lete apparatus for reclaiming scrap meta s which will be substantially automatic inoperation, willb'e easy and cheap tooperate and will occupy the minimum amount of floor space.

Other objects will appear and be pointed 'out in the following specification wherein a l preferred correlation and arrangement of parts 1s set forth in some detail.

'molten metal and dross;

Fig. 5 is a side elevation, partly in secf In the drawings, Figure 1 is a side eleva 4 is a sectional view thru the melting furnace with the stirring paddle shown in elevation and in relationto the agitated tion, ofthe assembled stirring paddle and shaft;

Figs. 6 and 7 are, respectively, elevation and cross-sectional views of the shaft;

Fig. 8 is a side elevation of one of the blades of the stirring paddle; and

Fig. 9 is a plan vlew of the bladepshown in Fig. 8; and I Figs. 10 and 11 are, respectively, views taken on lines 10--10 and 11-11 of Fi 8.

In practicing the process as disclose in the copending application above referred to we employ a melting furnace comprising a pot 1, which may conveniently be'mount'ed ture indicated at 2 in Fig. 1. Oil or other fuel burners 4 which directl the flames,

level ofV the floor or inwany other position.

within a circular chimney-like brick struces' i suitable to a proper heating of the pot and I.

metal contained therein.

A hood 5 connecting with a flue*V (not i shown) is arranged above the pot 'and is capable of lbeing raised and lowered to permit removal of the pot and cleaning ofthe furnace. Suitable superstructure such as that indicated generally at 6, and consistinglf uprights and cross-bars fonmounting the necessary shafting, pulleys, etc., is provided adjacent the furnace. Extending vertically thru the superstructure 6 isa shaft or hollow tube 7 provided with a longitudinally extending key 8 for engagement with a keyway (not shown) carrled by pulley 9 slid- .ably mounted on the shaft near its u per the yoke a ro terweight 13 provides means for raising and lowering the shaft 7. If desired, the cable 11 or an extension thereof (not shown) may be attached to a hand-winch, (also not shown) to render positioning of the shaft controllable at will and to permit accurate positioning of the shaft at any deslred point.

Adjacent the upper end of shaft 7 .1s .located a transverse shaft 14 connected with some suitable lsource of power (not vshow n) and bearing a pulley 15 in alignment wlth the pulley 9 and connected thereto by a b elt 16 whereby rotational motion of the shaft 14 is communicated 'to shaft 7. The shaft 14 carries an irregularly shaped section 17 u on which is mounted a yoke 18, the comblnation of this yoke and irregular section of the shaft resulting in a rapid vibratory motion of the oke 18. To the underside of d7 19 with a forked lower end 19' is attached andextends downwardly to engage with trunnions 20 on a chute 21 and serves to transmit a vibrating or shakin motion to the chute. The outer end o chute 21 is preferably supported by a cable 22 from the superstructure so that when not in u se its inner end',`which normally projects over the melting pot, can be elevated and rested upon the superstructure, as is shown in place bya thru-pin 25. However, in case shaft 7 is solid an extension thereof of small diameterl may be fitted into a hollowed portion 26 of the stud 24 and secured thereto by 'any suitable means. A'tthe lower end of the stud 24 and secured thereto by a bolt 27 are a pair of oppositely disposed stirring blades 28. Each lade has a collar portion 29 adapted to seat on the stud 24, an outwardly extending portion 30 of soscalled stream line formation from which a helicallyshaped portion'l Aof increasing pitch extends downwardly terminating in a tip portion 32 which is inclined abruptly to the under side of portion 31 and which also is provided with a front surface inclined outwardly. Y

When the two blades are assembled with theA stud 24 and shaft 7 they comprise a stirring paddle capable of giving the liquid metal in which it rotates a downwardly and then outwardly directed motion, creating thereby a vortex at the center of the liquid and outwardly andnpwardly directed currents along the sides of thc` pot as is indicated somewhat vdiagrammatically in Figs. l and" 4. A baffle, 1, which may consist of a p vrometer rod jacket attached to the inner snrthe face of the melting pot 1 retards the rotation of the liquid metal in a horizontal plane and directs the .metal toward the vortex.

More than one baiile may be used, if desired, the principle upon which their action depends being the retardation of the swirling motion of the melted mass along the inner surface of the pot with a consequent deepening of the. vortex by the action of the paddles at the properv slowspeed at 'which Vthe machine is operated.

Adjacent the furnace l is located a device adapted to receive dross removed from the furnace and .to convert it into a finely-divided condition from which the molten metal entrapped therein can readily separate. Various forms of apparatus could obviously be used for this purpose but a form which we have found satisfactory is shown in Figs. 2 and 3 of the drawings.

`This apparatus consists of a sheet inet-al frame 33 having .an upright end 34, side portions 35, and an inclined bottom 36. This frame carriesbearings 37 on its lower `side near one end in whichyare journalled eccentrics 38 secured to a transverse shaft 39. This shaft is actuated by a shaft 43 connected to a suitable source of power, thru pulleys 40 and 4l and a belt 42. By reason of the eccentric z-lrrangement, the frame 33 is vibrated vertically and horizontally so as to give a forward throw to particles passing 'along the tables when shaft. 39 is rotated.

Secured between the sides 35 of frame 33 are a plurality of cross tables 44 and 45, the former being inclined to the horizontal at a much steeper angle than the latter. Altho several such tables could be employed, if desired, we preferably employ only two a1'- ranged substantially as shown.

If desired, the bottom 3G of frame 33 may consist of a single table but, as shown in Fig. 2, it consists of a series of tables 46 scoured in overlapping position and adapt-.ed to receive material from table 45 and cominci'. it to the lower end of the frame A. screen 47 secured in position aty the cxtreme end of frame is adapted to receive material from tables 46 and to permit liuc dross material to escape thercthru while passing the larger particles of solidified metal on to its end.

In. addition to the bearing support 37 for frame 33, rods or other suitable suman-ting means 48 are attached at the lower end ol' the frame and to4 an overhead support.

A screen 49 is mounted on uprights 5t) .so cured to the sidesl 35 of frame 33 in position .to discharge materials onto table 44.

In practice the operation f our im proved apparatus is substantially as follows: A quantity of molten .metal is tirst placed in the furnace and then. the stirring paddle is lowered theleinto, by means of the raising,v of counterweight 2 and the consequent lowering of shaft 7, until'the tips 32 of the paddle just clear the bottom 'ofthe pot. otatmg motion is imparted to the shaft 7 and stirring paddle 23. At the same time chute 21 is lowered into the position shown by full lines in Fig. 1, the rod 19 being en gaged with the trunnions 20. Scrap metal in the form of turnings, borings, foil-or the like is placed in the open end of the'chute 2l' and by reason of the vibrating motion imparted to the chute by the rod 19 and yoke 18 it is caused to feed in a slow, substantially continuous steam into the vortex' Vthe pot for a sulicient length of time to permit melting. Impurities, oxides and other materials constituting dross collect at the surface of the molten bath where combustible matter is ignited and burns. Dueto the fact, however, thatthe dross has about' 'the same specific gravity as certain light metals -such Vfor instance, as aluminum, magnesium, etc., not all of the dross separates itself from the metal and rises vto the surface. Consequently when the pot has become filled to capacity with metal and dross, the stirring paddle, which has been 'gradually raised as the levell of the molten metal rose in the furnace, is now lowered to the bottom of the furnace and allowed to rotate in this position for a period of time whereby the dross entrained in the metal becomes concentrated at the surface thereof.

The paddle is next removed from the furnace by eleva-tion of the shaft 7, chute 21 is moved to the position indicated by dotted lines in Fig. 1 and afterl the dross 011 the surface of the molten metal has been treated by chemical reagents or otherwise it is removedand placed in-screen 49. Considerable molten metal drains out of the dross 'as it is being removed from the pot but the metal still retained therein is carried along with the dross to the screen 49 which is Joeing rapidly vibrated and which operates to f disintegrate all lumps and to reduce the dross to a finely-divided condition from which the molten metal canrapidly escape.

The fine dross and molten metal passing thru the screen 49 falls upon the steeply 1nclined table 44 vdown which it travels rapidly and by which it is tossed upwardly by the'vibrations of the table.

The effect ofthe rapid movement along the table 44, together with the fact'thatthe metal is subjected to the ,chilling action of the surrounding atmosphere, results in al* most instantaneous' chilling of the molten 'ing bath in a substantially metal to a temperature below that at which 1t readily oxidizes.

Upon passing to table 45 the speed of the 'movement forward ofthe metal is somewhat diminished but it is caused to bounce'along due to the vibration vof the table and in many cases to unite with other globules of the still molten metal. By the time the material has reached the end of tables 45 it has solidified and will pass over the screen 46 and into a receptacle 5l while the nely-divided dro-5s findsI its .way thru the screen and collects'as indicated at 52 in Fig. 2.

The metal in receptacle 51 which is substantially free from all impurities and which is only slightly oxidized may then be returned to the furnace l and re-melted. Previous to the return of this recovered metal, however` it is necessary to remove from the pot the excess of molten metal, retaining therein, however, suiiicient molten' metal to form a bath for the next batch of scrap metal to be refined.

Te do not desire that our should be limited to the specific parts, devices or arrangements above-described since other means suitable yfor accomplishing our objects and falling within the limits of o ur invention may occur to those skilled in the art. Accordingly, the scope of our vinvention is to be defined and limited onlyV bywhat is claimed.

What is claimed is:

invention l. An apparatus for reclaiming light'-I readily oxidizable metals comprising in combination, a melting furnace, molten metal agitating means-fin the furnace, means for actuating said agitating means, means for feeding scrap metal into the furnace ina substantially continuous stream, and means for .concentrating the dross on the surface of the molten metal.

2. An apparatus for reclaiming light 4readily oxidizable metals comprising in combination, a furnace adapted to contain molten metal constituting a melting bath,

means for feeding scrap metal into the melting bath in al slow, substantially continuous stream, and means for submerging the scrap metal in the molten melting bath and `for separating the dross of the melting bath from the molten metal, and collecting the same on the surface of the said bath.

3. An apparatus for reclaiming light readily oxidizable metals comprising in combination, -a furnaceadapted to contain molten metal consituting a melting bath, means for feeding scrap met-al into the meltcontinuous stream, means comprising a rotatable paddle for causing circulation of the lnolten metal and for concentrating the dross onjthe surface of the melting bath. y

4. An apparatus forl reclain'ling light readily oxidizablemetals comprising in llO combination, a furnace adapted to contain a molten metal melting bath, means for submerging scrap metal inthe melting bath and concentratingdross on the surface thereof comprising a rotatable paddle adapted to be lowered into and removed from the melting 'bath and having arms adapted to produce upwardly and downwardly directed currents 'in the molten metal bath when the paddlel is rotated therein.

5. An apparatus for reclaiming light readily oxidizable scrap metals comprising in combination, a furnace adapted to contain a lmoltcu'n'ietal melting bath, a itating means comprising a rotatable pad le having a plurality of helically-sliapcd arms of varying 'pitch terminating in downwardly and outwardly inclined tips, and means for lowering the agitating means into Athe furnace and raising it therefrom. 1

6. An aiparatusfor reclaiming lightreadily oxidizable inetals comprising in combination, a furnace adapted to contain a' molten metal melting bath, a rotatable paddle in the furnace adapted to create a vortex in the melting bath, means for feeding scrap metal into the said vrtex and means'for moving the paddle into and out of the bath during rotation thereof.

7. An. apparatus for; reclaiming 'light readily oxidizable metals comprising in combination, a furnace adapted to contain a molten metal melting bath, means for feeding scrap Ametal into thefurnace coinprising a conveyor' and shaking means therefoi, and a rotatable paddle adapted to cause circulation of the molten bath.

8. An apparatus for reclaiming light readily oxidizable metals comprising 1n combination', a melting furnace `for containing molten nietal, means for agitating molten lmetal in the furnace and for concentrating the light impurities in molten meta-l in the furnace as dross on the surface of the molten metal, and means for actuating the said a agitating means and for permitting the agitating means to be raised and lowered during rotation thereof.

A9. .An apparatus for reclaiming light readily oxidizable metals comprising in combination, a furnace adapted to contain molten metal constituting a melting bath, means for quickly submerging in the molten bath scrap metal delivered to the surface thereof and for concentrating the dross of the melting bath on the surfacethereof.

10. An apparatus ,for reclaiming finely Y divided light, readily oxidiz'able scrap metals comprising in combination, a furnace adapted to contain molten metal, constitut- -iug a melting bath. the said furnace having an upright baille along its inner surface, a rotatable paddle in the bath adapted to causel lmaintained upwardly and downwardly directed currentsof circulation of the molten bath and for concentrating the dross on the surface of the melting bath.

11. An apparatus for reclaiming finely divided light, readily oxidizable scrap metals comprising in combination a furnace for molten metal havingan upright baille on an inner surface thereof, a. paddle adapted` to be rotated in the said furnace, the said paddle comprising downwardly extending outwardly inclined arms terminating 1n abruptly bent tip portions, .the paddle being adapted to cooperate with the said baille 'p and producel and maintain continuous upwardly and downwardly directed currents in the molten. metal.

. A12. An. apparatus for reclaiming scrap metal comprising in combination, a furnace provided with an upright baille on its ,inner surface, a, rotatable paddlelhaving downwrdly extending arms terminating in ab uptly bent tip. portions, the under surface of the said ti portions inclined outwardly and means or supporting andlrotating the paddle in the furnace.

13. An apparatus for reclaiming scrapA metal comprising in combination, a furnace provi-ded with an upright ballie on its inner surface, a rotatable paddle having downwardly extending arms terminating in abruptly bent tip portions, the under surface of the said tip' portions inclined` outwardly and means to lower the paddle into the furnace, to rotate it therein and to raise y it out of the furnace.

142 An apparatus for reclaiming scrap'.

loo

metal comprising in combination, a furnace j provided with an upright battle on its inner I surface, a rotatable paddle having downwardl'y extending arms terminating in ,e

abruptly bent tip portions, the under surface of the said tip portions inclined out wardly'and means to move the paddle into and out ofthe furnace and to rota-te itat4 'bath and agitating-meanscomprising a-'rotatable paddle having helically shaped blades of increasing pitch and terminating in downwardly and outwardly inclined tips.

17. Apparatus for reclaiming metal comprising a receptacle for a molten metal bath, a rotatable paddle in said receptacle maintaining upwardly and downwardly circulating currents in the bath andi concentrating Luo.

Lcarried by circulating dross on the surface of the bath, and means the recefptacle opposingA currents clrcum tacle. K'

18. In an apparatus fo,f1fc1a1ming.meta1 and having a rotatable paddle in a receptacle fora moltenlnetal bath, paddle blades downwardly and thenroutwardl inclined'to produce currents substantially ollowing the erentially of the recep-` by the receptacle for resisting currents cirsrface'of an an'nulus and flowing down- 1'0 wardly at theinside and upwardly at the outside of said a.nnu1us, and means carried cumferentially of the receptacle.

turesrV ',frHEROND.'STAY.

- C HA'RLES o. TESSiER.

`Iniestimony whereofwe aiiixl our sig-'na- 15 d 

